Soot blower of the short-travel retracting type



Dec. 15, 1953 Filed Aug. 5, 1947 LE ROY s. DE MART 2,662,241

sooT BLOWER 0F THQ SHORT-TRAVEL RETRACTING TYPE 3 sheets-sheet 1INVENToR. 25? Je/aff Dec. 15, 1953 LE ROY s. DE MART SOOT BLOWER OF THESHORT-TRAVEL RETRACTING TYPE 3 Sheets-Sheet 2 Filed Aug. 5. 1947 IN VENTOR. @Katy Fe/)721111.

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Dec. l5, 1953 LE ROY s, DE MART 2,662,241

sooT BLOWER oF THE: SHORT-TRAVEL RETRACTING TYPE Filed Aug. 5. 1947 3Sheets-Sheetl 5 IN V EN TOR.

atented ec. l5,

sooT BLOWER F THE SHORT-TRAVEL: RETRACTING TYPE Le Roy S. De Mart,Detroit, Mich., assignor to Diamond Power Specialty Corporation,Detroit; Mich., a corporation of Ohio Application August 5, 1947, SerialNo. 766,183

Claims.

This invention relates to soot blowers which are projected into theboiler during the blowing operation and are retracted to a protectedposition during the intervals between blowing operations.

The main objects of this invention are to provide a soot blowerincorporating an improved retractable blower tube which is protectedfrom dust and dirt particularly during its non-use between blowingoperations; to provide asoot blower construction in which the tubecarrying the cleaning fluid is very rigidly mounted and securely heldduring the blowing operation; to provide an improved soot blowerconstruction in which leakage of the cleaning fluid during the blowingoperation is held to a minimum; to provide a soot blower construction inwhich the various packings and packing glands are more readilyaccessible for adjustment and replacement than in presently knownconstructions; to provide a soot blower of the projecting and retractingtube type which is compact in overall size and which utilizes a standardpart made in large production for its supporting frame and to provide asoot blower construction in which it is assured that the cleaning fluidcontrol valve will not be opened until the cleaning nozzle is in a fullyprojected position.

The present invention constitutes a further development of thatdisclosed in the copending application of Harry E. Brelsford, Serial No.643,055, iiled January 24, 1946, now Patent No. 2,486,585, issuedNovember 1, 1949, and assigned to the assignee hereof.

An illustrative embodiment of this invention is shown in theaccompanying drawings in which,

Fig. 1 is a view partly in vertical longitudinal section and partly inside elevation, showing a blower head and associated mechanismconstructed in accordance with the present invention, with the blowertube in retracted position and some of the parts broken away;

Fig. 2 is a view similar to Fig. 1 but showing, the position of theparts when the blower tube is in fully extended position;

Fig. 3 is a fragmentary transverse vertical sectional view takensubstantially on the line 3--3 of Fig. 1 and looking in the directionindicated by the arrows;

Fig. 4 is a thin sectional detail taken substantially on the line 4-4 ofFig. 3 and looking in the direction indicated by the arrows;

Fig. 5 is a perspective view of the latch piece;'\ and Fig. 6 is afragmentary longitudinal sectional view of a modied construction.

In the construction shown in Figs. 1-5 of the drawings, a supportingframe for the structure comprises a gooseneck casting generallydesignated 4 which also serves as a fluid inlet conduit and whichextends upwardly from an annular 2 fiange 6 by which the structure isbolted to a pipe or other source of cleaning fluid.

A bracket 8 is secured by cap screws I0 to the casting 4 and extendsupwardly and terminates ina vertically disposed annular head I2 which isin spaced horizontal alignment with the upper end of the gooseneck 4.The structure is tied together with great rigidity by means of anintegrally formed .bracket I4 extending angularly upwardly from thegooseneck 4 and a corresponding bracket I6 integrally formed on the headI2, the upper ends of which brackets are rigidly tied together by ahorizontally disposed tie rod I8 having nuts 2i] and 22 threaded onopposite ends thereof. The rod I8 is reduced adjacent its ends to formsuitable shoulders against which the upper ends of the brackets I4 andIii are rigidly held by the nuts 20 and 22 respectively.

The gooseneck 4 is of hollow construction to form a conduit 24 forcleaning fluid introduced thereinto through a valve seat 26 controlledby a valve 2S. Valve 28 is mounted on the lower end of valve stem 30which is axially slidable through an exteriorly threaded valve guide' 32which is mounted through the upper wall of the casing 4 in axialalignment with the valve seat 26. A restricting disc 34 is adjustablythreaded on the lower end of the valve guide 32 for controlling theamount of cleaning fluid passing through the valve seat. 'Ihe upper endof the valve stein 30 is provided with a mushroom cap 36 in the usualmanner against the underside of which bears the top end of a helicalcompression spring 38, the lower end of which bears against anout-.turned radial ange 40 integrally formed on an inverted cup 42 whichhouses a plurality of packings 44 for sealing the valve stem against gheesctalpefof cleaning uid. The spring 33 perorms e unction of hol on itsseat 26. ding the valve 28 closed The upper end of the gooseneck conduit24 therethrough terminates ina aqallivcirli .zontally disposed socket55, opening toward and in alignment with the axis of annular iange I2 ofbracket 8 and this socket is counterbored to receive a pair ofconcentric tubes, the outer of which, 46, is sealed at its left end asviewed in Fig. 1 by packing 48 normally held compressed by packing gland50 secured by bolts 52 positioned at diametrically opposite sidesthereof. The inner end of the packing 48 abuts against a bearing sleeve54 which journals the left-hand end of the outer tube 46 so as to permitboth rotation and limited axial movement of the tubes The right-hand endof the tube 48, or inner endl as it is generally referred to, isjournaled in a bearing sleeve 56 which is mounted in a sleeve 58 with apacking 60 compressed by packing gland 62 interposed between the sleeve58 and the exterior surface of the tube 4B. The packing gland 62 is heldby a plurality of threaded studs 64 havingnuts 56 `oiitlieir outeiedsand.bei'ng threadedl into" the axiar face bf a drive" gear s's which ismounted on the exterior surface of the sleeve 58 and secured againstrelative rotation with respect thereto by a key.x'1 ,0.

The sleeve 58 at its right-hand end is `rigidly secured as by welding toa driving nut '|2 hich Iis journaled in an anti-friction bearing' 14tinted in a counterbored recess foriedo'oncntic the face of the annularhead I2. A bearing taining plate 'I6 is secured against the outer faceof the head I2 by a plurality of screws '1:3 having their headscountersunk in the plate 16 s'a'slt'o be flush with the outer-'surfacethereof.

The nut.|2 is rotatably `andslidably ttedupon an inner tube '80', withwhich -it is 'thre a`.'de'dlyl fin- :terengaged by means' of ahelicalkey'84 interiorly .fastened to-and` proj ectinginwardly from theniii'.J2 and engaging in alhelic'al'groove 02' formed'in the exterior.surfaceof the' tube 80. The outer surface of .the inner tube |30` atdiametricallypposte points isv provided with axially'extending keyways85 and B8 for receiving'ke'ys 90 92,

respectively, which are passed thrcughslots (undesignated) formed in theinner `end 'of 'the outer ,tube 43 and rigidly secured thereto as bywelding.

.The length o the .tube 4.6 is such that when the parts are in thepositioning'shown in Fig. lfoi 'the drawings, tube 4.6 is in spacedrelation to the nut .1.2, as shown at 94, .the space 94 determining theamount'of axial movement of the tube' 45m' its supporting sleevebearings 54 and 55.4 The innertube 80 is held against turning withrespec't'to tube 46 `by the key and slot connecting means `SIL-,36 and.e2-B8, while the tube 80 is longitudinally actuatable byturning the nut"i2, aswillfbe apparent. The right-hand end of the inner tube 80 isinteriorly threaded .to receive one end of -exlteriorly threaded blowertube 95, the opposite 'or outer end of which isv provided with a 'blowernozzle .9,8 having a plurality of discharge orifices '|00 therein asisusual .in constructions of'vthis general character. Means are providedfor rotating the-gear wheel 6MB, sleeve 5,8 and'nut .l2 fori projecting`and'ffresracting the innertube 80. The rotating means comprises a chainsprocket wheel '|02 journale'd on one end of .thetie rod|8 and havingits hub lI 4 fast vwith respect to one end ofthe sleeve |00, ,theopposite end of which is connected to a fpinibn gpc whicumesheswithteeth no of a gear wheel .613. The pinion |08 isjournaled on theshaft "I8 at the end thereof opposite to the sprocket wheel |02 and thepinion and gear are partiallyv covered and protected by a housing coverI |2 in the usual manner. The outer tube 45 has a` radially extendingmounting ange |,I4 rigidly secured thereon by abutting against ashoulder integrally formed on the exterior of the tube and secured byset screw I I@ which, in turn, issecured by set screw I |8,` the innerend of the screw I l5 b'eingfof'reduced 'diam'- eter and extending intoa shallowsocket formed in the exterior surface of the tube 46 'inappro"- priately .spaced relation to the shoulder thereon against whichthe hub of the .flange ||4 abuts. 'I'he'ange |4 has a cam I20irigid1ysecured thereto by one or more bolts as |22.' The cam is generallyannular in shape with a portion thereof cut out as is usual inconstructions of this character and @oaths .with and is adapted tofopjcrate the upper end of a trigger |24,V the lower endof which'ispivotally mounted by a pin |26 on vns the upper end of a bracket |28which is integrally gforrnedontle'base portlonof'thecastingf.Triggerf'l24 near its/lower n'd is provided with an integrally formedlobe |30 which is adapted to Yrest upon cap 36 and force the samedownward as fshownlin Fig.'3 and which is mounted on one end"of'a'boltI`42 The bolt |42 .is `horizontally and laxially slidablethrough the trigger |24, in which Jit'lis'supported by a bushing |4I.The end of Athe .bolt opposite tothe latch |40 `projects .from .theopposite face of the trigger and carries a helical compression spring|44 'one end of which abuts andgbears againstthe face of the trigger |24and the other end of which bears against a washer adjustably secured .inan appropriate position by a nut andlock nut |46 which are ,threadedon'th/e end of the `bolt |42.

The latch I 40 is also yieldably urged clockwise, as viewed in Eig. A3,to the position shown in full lines inthat view,.by'a helical tensionspring |49, one'end of which is anchored to a pin |50 rigidly mounted onthe' side of the triggerl .|24 and the other end of which is secured tothe .latch |40 at `point corresponding to the axis of an anchor Apin'|52 located inspaced relation to the axis of the bolt |42 so as to tendto rotate the latchl |40 -rinar clockwise direction as viewed` in Fig. 3ybut permitting thesame to swing outwardly in anti- `clockwise directionagainst the action of. .the spIing'IAS. Pin |50 also serves as a stop to.limit f'clockwise rotation of latch |40.

The upper end of the trigger |24 is provided with a shoe |54 which is ofslightly greater width .than the trigger |24` and which serves as abearing forcontacting cam |20. It is to be noted that the. width of`,the shoe |54 and of the cam' |20 is such thai-...the shoe bearsagainst the outer pel ripheral surface of .the cam` |20 at all times're-,gardless lof 4the position of the cam and outer tube. In other words,the outer tube may be shifted to the right to the extent of theclearance space and theshoe |54 is maintained in bearing contact on theouter surface of the cam |20 as shown in Eig. 2 of the drawings. Theleft'endofthe inner tube 80 as viewed in Figs. land 2.0i the drawings isof reduced out'- slde diameter to form a shoulder against which abutsthebase leg of a combined packing follower and bearinglaof L-shaped crosssection. I

The peripheral face of the vertical leg of the member] 58 slidably tsthe inside diameter" of the outer tube 46 and its axial face wall abutsagainst a pluraltyof packing rings |60. The packing rings |60 areretained by an internally threaded ring |52 screwed' on i the exteriorlyYthreaded end ofv tube 8,0, and locked thereto by sijitablejmeans. Theperipheral surface of the 'rn'g|62 also has a sliding t within theinterior of the outer tube 46 and also serves as a bearing between thetubes.

In the operation of this device the chain sprocket |02 is rotated eithermanually or by a power motor thus imparting rotation to the pinion |08through the sleeve |06. Pinion |08 meshes with and drives the gear wheel63 which through the key 'i0 rotates the sleeve 58 and nut l2 which isjournaled in the ball bearing 14. Rotation of the nut 12 causes, inaccordance with the direction of its rotation, projection or retractionof the inner tube 80 by moving the same axially, as will be apparent.During such axial movement, tube 80 is prevented from turning by thekeys 90 and 92 which prevent relative rotation between the inner tube 80and the outer tube 46. The outer tube 46 is, in turn, restrained fromrotation by engagement of the shoulder |34 of flange |4 against the stop|36, which is rigidly mounted on the side of trigger |24. As the tube 80completes its projecting movement to the right preparatory to a blowingoperation, the packing follower |58 engages the left ends of the keys 90and 92 and thereupon shifts the keys, and the outer tube 46 to which thekeys are at tached, axially to the right from the position shown inFig'. 1 to the position shown in Fig. 2, whereupon the keys and the endof the outer tube 46 abut against the rotating nut l2. This shifting tothe right carries the latch |40 to the right against the action ofcompression spring |44 (because latch |40 overlaps the boiler side oflug |34 on flange I4, which is fast upon outer tube 46, see Figs. 2 and3). The amount of axial movement is such that the shoulder |34 of flange4 is disengaged from the stop |38 on trigger |24, whereupon rotation ofthe outer tube 46 is permitted. Continued rotation resulting from. thecontinuing actuation of the chain wheel causes the toe portion |2| ofcam |20 to swing the upper end of the trigger |24 outwardly anddownwardly as indicated by the arrow |32 in Fig. 3, whereupon the lobedepresses the valve stem 30 thus opening the valve 28 by moving itfromits seat 26 and permitting cleaning fluid to ilow through the conduit24, tubes 46 and 60 into tube 96 and thus out of the nozzle 98 throughthe orifices |00. The stop |36 and the tooth |34 now lie in differentplanes and do not interfere with the aforesaid valve actuation. Whenthe: lug |34 moves out from beneath latchpiece |48, spring |44 moves thelatchpiece back to its normal position close to the trigger as shown inFig. 1. Engagement of the packing follower |58 against the keys 90 and92 also tends to cause' compression of the packing |60, thus eiecting atight seal during the blowing operation and effectively preventing thecleaning fluid from escaping through the sliding joint between the innerand outer tubes, while by virtue of this arrangement it is not necessaryto fit the packing so tightly as to impose undue friction, as wouldotherwise be necessary. The packing follower |58 also serves as a rigidsupport for the end of the inner tube S0 and the outer tube being well"-supported at its opposite ends in the bearing sleeves 54 and 56, theentire rotating structure is rigidly supported during the blowingoperation. It will be understood that the operator may continue to turnthe chain wheel in the same direction as long as desired to insureproper cleaning, and the cam |20 will open the valve for thepredetermined portion of each revolution which its angular extentdictates.

'Upon reversal of the direction of rotation ot the chain and chainwheel, and so of the nut 12, for retracting the tube 80, the inner andouter tubes may rotate together with the inner tube remaining projecteduntil, asA the toe portion |2| of the cam |20, turning clockwise asviewed in Fig. 3, clears the outer end of trigger shoe |54, the triggeragain moves inwardly toward the tube axis to the position shown in Fig.3. The lower end of the shoe |54 is provided with an abrupt or sharpportion |55 which at this time moves into the relieved or cut outportion of the camV and overlies a radially disposed heel portion |23 ofthe cam to block further clockwise rotation (as viewed in Fig. 3) of thecam and of the tubes 46, 60. Continued rotation of the sprocket and nutin the same (reverse) direction thereafter drives tube 30 in a returnmovement back into tube 46. As tube 80 completes its retractingmovement, the ends of slots 8B, 88 engage keys 30, 92 and move them andthe tube 46 to the left to its extreme position shown in Fig. 1. Tooth|34 may then project beside and overlap the side or the thinner webportion of latchpiece |46 farther from the boiler, as before, but itwill be seen that if the sloping back (outer) face of the tooth engagesthe latchpiece during the counterrotation of the cam and flange assemblyand before tube 46 has moved all the way to the left7 latchpiece |40 mayswing out of the way, simply turning counterclockwise on its pivot pin|42 and stretching spring |49. The parts are thus restored to theirinitial positioning depicted in Figures l and 3.

1n the modified construction shown in Fig. 6

parts analogous to those already described are identied by likereference numerals distinguished by the addition of the letter A toeach. In this construction the latchpiece |40 is eliminated and thereturn spring |44A which replaces the spring 44 is in the formof ahelical compression spring encircling the outer tube 46A and. reactingat one extremity against the collar ISA. and at the other extremityagainst packing gland. 62A, a washer as 64A being interposed between-lthe spring and gland. The gland is constantly urged by the springagainst the packing material A.

The cam plate l |4A is provided with a radially project abutment portion|34A adapted to bear against a lug portion |36A carried by the trigger|24A, the tube assembly being thereby held against rotation when theouter tube is at the leftward extremity of its movement, as shown .inFig. 6. It will be noted that the spring |44A 4constantly urges theparts to and yieldably maintains them in this position under normalconditions. When with the outer tube held against rotation in the mannerindicated the actuating nut is turned to project the inner tube A, theaction of the parts will correspond to that of the embodiment lirstdescribed, and in like fashion, when the inner tube reaches the end ofits movement, it pulls the outer tube to the right, Adisengaging theabutment |34A from the lug 436A, as the cam ||4A moves to the right withthe outer tube 46A. Thereafter the two tubes may rotatein unison, as inthe previous embodi-1 ment,v and the blowing action may take place`during the entire or any desired portion of the i; rotary movement ofthe fully projected tube assembly, as will be apparent.

When, with either of the above described embodiments, the actuatingmeans is operated in the reverse direction to tend to retract the innertube, the twov tubes may tend to rotate in unison,

of said projection for overcoming said yielding means and therebyreleasing said shoulder and stop from engagement whereby said outer tubeis free to rotate with said inner tube and means controlled by therotation of said outer tube for introducing cleaning fluid to saidconduit and tubes.

8. In a soot blower, a supporting frame including a conduit for cleaningfluid, a tube mounted on said frame for both rotative and axialmovement, said tube communicating with said conduit, the exterior ofsaid tube being provided with a helical groove forming a coarse thread,a nut surrounding said tube and threadably engaging said groove, saidnut being journaled in a fixed axial position, an outer tube journalcdon said frame in position to surround and normally cover said threadedtube, said outer tube being mounted to have limited axial movement, ashoulder carried by said outer tube, a stop carried by said frame forengaging said shoulder to restrain said outer tube from rotation, keyingmeans preventing rotation of the inner tube relative to the outer tube,yielding means for maintaining said shoulder and stop in engagement,means for rotating said nut to project said threaded tube axially fromsaid outer tube, means responsive to movement of the inner tube to afinal stage of said projection for moving said outer tube axiallyagainst the action of said yielding means and thereby releasing saidshoulder and stop from engagement whereby said outer tube is free torotate with said inner tube and means controlled by the rotation of saidouter tube for introducing cleaning fluid to said conduit and tubes.

9. In a soot blower, a supporting frame, a nut axially fixed androtatably mounted on said frame, an inner tube threaded through saidnut, an outer tube journaled on said frame and surrounding said innertube and having one end portion limitedly axially movable with relationto said nut, yielding means normally maintaining said outer tube inaxially spaced relation to said nut, a key on one of said tubes axiallyslidable in a keyway in the other of said tubes, means restraining saidtubes from rotating only when said outer tube is in such spaced relationto said nut, means for rotating said nut to project said inner tube fromsaid outer tube, means responsive to movement of the inner tube to aiinal stage ci such projection for moving said outer tube axiallyagainst the action of said yielding means, such axial movement of saidouter tube freeing said tubes for rotation and means for supplyingcleaning uid to said tubes.

10. In a soot blower, in combination. with a supporting frame, a pair oftelescopically intertted tubes, including a rotatable outer tube, aninner tube longitudinally slidable to project to greater or lesserextent with respect to the outer tube, a screw threaded portion carriedby a part of the inner tube which is housed within the outer tube whensaid inner tube is fully retracted into the outer tube, a drivingelement engageable with said screw threaded portion to move said innertube longitudinally with relation to the outer tube, latching meansincluding a releasable latching element engageable with the outer tube,slidable keying means coacting with said latching means andinterconnecting said tubes for preventing unwanted relative rotation ofsaid outer tube and inner tube during longitudinal movement of the innertube, and an abutment portion operatively connected to said latchingelement and engageable by said inner tube when the latter is moved toprojected position to release said latching element and thereby topermit simultaneous rotation of both tubes.

l1. In a soot blower, in combination with a supporting frame, a pair oftelescopically intertted tubes including a rotatable outer tube, aninner tube longitudinally slidable to project to a greater or lesserextent with respect to the outer tube, a screw-threaded portion carriedby a part oi the inner tube which is housed within the outer tube whensaid inner tube is retracted into the outer tube, a driving elementengageable with said screw-threaded portion to move said inner tubelongitudinally with relation to the outer' tube, means including areleasable latching element engageable with the outer tube, slidablekeying means interconnecting said tubes for preventing unwanted rotationof said outer tube and inner tube during longitudinal movement of theinner tube, an abutment portion operatively connected to said latchingelement and engageable by said inner tube when the latter is moved toprojected position to release said latching element and thereby topermit simultaneous rotation of both tubes, said outer tube beinglimitedly longitudinally shiftable by the inner tube as the latterapproaches fully projected position, said abutment portion being carriedby said outer tube and the latching element being operatively connectedto the outer tube whereby such longitudinal shifting movement of theouter tube may serve to actuate said latching element.

12. In combination with means as set forth in claim 1l, means forsupplying cleaning uid to said inner tube, means for controlling thefluid supply including a valve, actuating means for said valve includinga cam member carried by the outer tube and a follower member engageableby the cam operatively connected to the valve to actuate the latter, thecam and follower members being of sucient length axially of the tube sothat such cam and follower may remain in engagement throughout the fullrange of longitudinal shifting movement of said outer tube.

13. In a soot blower, in combination with a supporting frame, a ipair oftelescopically intertted tubes both of which are rotatably mounted inthe frame and one of which is longitudinally slidable with respect tothe other, means keying said tubes against unwanted rotation withrespect to one another, nut and screw portions for moving one of saidtubes longitudinally to project and. retract the same, the other of saidtubes being held against unwanted longitudinalmovement, means forholding the tubes against unwantedY rotation including an abutmentportion on the other of said tubes, a latching element engageable withthe abutment portion, means responsive to longitudinal movement of theprojectable tube for disengaging said latching element from theabutment, and spring means yieldably urging the latching element intoblocking relation with respect to said abutment, said spring meansworking in a direction parallel to the direction of longitudinalmovement of the projectable tube.

14. A soot blower construction as defined in claim 13 whereinsaid springmeans comprises a helical spring surrounding the outer tube.

15. A soot blower construction as defined in claim 13 including meansfor supplying cleaning nuidto they inner tube, the outer tube being11mitedly. longitudinally-,shiftable to actuate saidlatchingelementto-and from blocking relation,

aangaat l'li Said Spring meanflatllgupon. Said: Giltl: time to.rieldably-'Oppcsemovemcnt offthclutching` clementf-rom suoli blockingrelation.

16. A soot, blowerfasfdefneddn; elaim 13;: includ-l ing means' forsupplying cleaning. iluid toV the inner'y tube, aV valve for controllingthe,` iiowA ofl such. fluid, actuating means-for the-valve including acam movable concurrentlywithsaidjlatching element, and. a follower, saidabutment being carriedby said follower.

1-7. A soot blower as; iefinedV in claim 13` in.- cluding-:means forsupplyingcleaning fluid tothe inner tube, a. valve for controlling theflow of suoli uid, actuating mea-ns for the valve includingA a cammovable. concurrently with said latening element, and a, follower,--Asaid;springY means being carriedibysaid toilower.

18. Ascot blower as fdened-.in claim-13 including means forSupplyingcleanin'g; fluid tothe inner tube, a valve for controlling;`the; flow of such; fluid, actuating means for the` valve includ-- ing acam` movable. concurrentlyI withsaid latching` element, andi a follower,and said spring` means beingcarried by said.t outer: tube;

, 19, A soot blower construction. as defined in claim l-3`inoludingmeans'for supplying cleaning fluid tothe inner tube. the outertube. being limitedly longitudinally' shftable to actuate said latchingelement to.u andv trom: blocking relation, a valve for controlling. theow of such` fluid, actuating means. for thev valve including a" cam,carried by and. shif-table-withthe outer tube, and a follower held.against such shifting movement. and engageable byf the? cam, said;latching element being carried bysaid, outer tube and saidl abutmentbeing substantiallyl fixed against such longitudinal shifting movementand against rotation with. saidA outer tube.

20. A soot blower construction asdefined in claim 1-3 including means`forsupplying cleaning fluidv to the inner tube,4V the; outer tube beinglim.- itedly longitudinally shiftable to, actuate said. latching elementto andl from blocking relation,A a valve for controlling' the: flowofsuch fluid.. actuatingV means for the valve; including a cam carried byand shftable with the outer tubeand a follower held4 against Sllhshifting; movementY and, engageablebyv thefcaim said latching; elementand said; spring means' being carried by said outer tube andsaidabutment being;l substantially fixed against such longitudinalvshifting movement. and against. rotation with said outer' tube.

21.. A soot.l blower construction as defined in. claimr 131includingmeans forsupplyingv cleaning: fluid. to the innertubc. the cuter tubebeing limitedly longitudinally shiiiable te. aotuate said latchingelement to and` from! blocking relation, a valve for controlling: theilove of; such fluid, actuating means for the valve? including a camcarried by andY shiftablef with' the; outer tube, and a followerheldagainst such; shifting movement' and engageable bythe cani;4 saidlatching elemeirit.I being carried by' said; outer tube, saidsp1-ingmeans being carried by the follower, and said abutment being.substantially fixed against such longitudinal shifting movement andagainst. rotation with said outer tube.

22. Ina soot blower,y asupporting frame, an outer tube rotatably mountedon.. said. frame, an inner tubev axially slidable within said outertube, said tubes being non-rotatable. with respect to each other. meansfor moving; said inner tube axially to. proiect the Same trom said outertube, means for restraining, said outer tube against. rotation. duringthe projection. or said moet tube..

responsive-tomovement of the inner tube tea iinal; stage of projectionfor releasingr said restraining; means. whereby,- botb tubes, mayA berotated inunisommeans for supplying a cleaning fluid` to said` tubes,and external bearing means rotatably-supporting said outer tube nearboth extremities thereof.

23. In. a soot blower, a supporting frame, an outer tube rotatablymounted on said frame, said tube beingV mounted to have limited axialmovement, an'. inner tube axially slidable within said outer tube, saidVtubes being keyed together for preventing. Vrelative rotationtherebetween. meansfor moving said inner tube axially to project thesame from said outer tube, means for restraining said outer tube-againstrotation during the projectionl of the inner tube, means responsivetomovement of the inner tubefto a final stage of projection for movingsaid outer; tube4v axially.- and; thereby releasing said restrainingmeans whereby both tubes may be rotated in unison, and external bearingrmeans rotatably supporting'said outer tubenear both extremities thereof.

24.- A soot blower as defined in claim l whereinsaidlatching meansincludes two elements, one

connected to the frame and the other to the outera tube'said-keyingymeans being carried partly by the, inner tube and partly by the outertube.

25. In a soot blower, in. combination with a supporting frame, a pair oftelescopically interfitted` tubes, including an inner tube and an outertube, the inner tube being longitudinally slidable with respect to theouter tube, means for sliding the inner tube toproject and retract thesaine, means for supplying cleaning fluid to said inner tube, packingmeans for sealing the space between. saidL tubes, means for tighteningsaid packingV meansagainst the exterior of the inner tube andtheinterior of the outer tube in response to, projection. of the innertube, including an abutment, portion` carried by said inner tube andmovable to a position to, exert pressure upon said packing means: as theslidable tube reaches the projected position, said inner tube beingslidable through asubstantial travel, the outer tube being also,limitedly slidable through a relatively slight travehan abutment portioncarried by the outer tube, the packing means being interposed betweensaid: abutment portions and compressible therebetween, when the innertube is fully projected, springl mea-ns opposing` longitudinal movementof; the outer tube inthe direction of projecting; movement: of the,inner tube, wherebyl when tbe inner tube, is fully projected by saidmeans for sliding the same the outer tube is also; longitudinallyy movedby force transmitted throughq said abutments and packing and theresistance. of the. spring means is also imposed upon the packing.

LE ROY S. DE MART.

References Cited in the -file of this patent UNlTED STATES PATENTS

